Metal rolling mills



y 3, 1956 H. J. KALBERKAMP 2,752,804

METAL ROLLING MILLS 8 Sheets-Sheet 1 Filed July 15, 1952 INVENTOR HER? JKALiisiiy P 76 I y 3, 1956 H. J. KALBERKAMP 2,752,804

METAL ROLLING MILLS Filed July 15, 1952 8 Sheets-Sheet 2 INVENTOR HERMAN J. KALBERKAMP 8 Sheets-Sheet I5 July 3, 1956 H. J. KALBERKAMP METAL ROLLING MILLS Filed July 15, 1952 W Mmm y 3, 1956 H. J. KALBERKAMP 2,752,804

METAL ROLLING MILLS 8 Sheets-Sheet 4 Filed July 15. 1952 INVENTOR HERMAN J. KALBERKAMP J y 5 H. J. KALBERKAMP 2,752,804-

METAL ROLLING MILLS Filed July 15, 1952 8 Sheets-Sheet 5 INVENTOR HERMAN J. KALwP g% yap/2 July 3, 1956 H. J. KALBERKAMP METAL ROLLING MILLS 8 Sheets-Sheet 6 Filed July 15, 1952 INVENTOR HERMAN J. KALBERKAMP J y H. J. KALBERKAMP 2,752,804

METAL ROLLING MILLS Filed July 15, 1952 8 Sheets-Sheet '7 H. J. KALBERKAMP 2,752,804

METAL ROLLING MILLS July 3, 1956 8 Sheets-Sheet 8 Filed July 15, 1952 INVEN'ITOR HERMAN J.KALBERKAMP United States Patent METAL ROLLING MILLS Herman J. Kalberkamp, Whitehall Borough, Pa., assignor to Mesta Machine Company, Pittsburgh, Pa., a ccrporation of Pennsylvania Application July 15, 1952, Serial No. 298,916

13 Claims. (Cl. 8055) This invention relates to rolling mills for large metal pieces, and more particularly to those mills generally known in the industry as universal slabbing mills, which have both horizontally and vertically disposed working rolls.

In universal slabbing mills the most practical and accepted driving arrangement for the vertical rolls is through bevel gearing from an overhead horizontal drive shaft with the driven bevel gears mounted either directly to upper extensions of the vertical rolls or mounted on separate vertical shafts and connected to the vertical rolls by means of intermediate gearing and couplings. These arrangements, however, present serious problems with regard to minimum shutdown time for replacement of the vertical rolls and with regard to reconciling the adjustment of the spacing of the vertical rolls to include very close spacing for rolling slabs of minimum section, with the substantially greater spacing required for gearing of the size and strength desirable for driving the vertical rolls.

In most forms of universal slabbing mills, the overhead drive shaft and associated parts of the frame have to be removed preliminary to replacing of the vertical rolls. This requires a relatively long shutdown time, running to about eight hours. In another form of universal slabbing mill, the drive parts may be left in place but it is necessary to demount one of the upper vertical mill cross frames, and this still requires several hours shutdown time. Both of these conventional forms of universal mills not only require the dismantling of some major part of the mill in order to replace the vertical rolls, but also call for mounting the bevel gears slidably along the overhead drive shaft in order to permit lateral shifting of the vertical rolls as required during rolling for reducing the workpiece and for rolling slabs of different widths. This slidable mounting of the bevel gears is undesirable because a mill of this type reverses the direction of rolling for every pass and the sliding connection between the drive shaft and the bevel gears must be made with sulficient clearance to permit such sliding. Due to the heavy loads encountered and the quick reversals desired, the initial clearance increases to objectionable play in a relatively short time. Moreover, lateral movement of the gear sets toward each other for the minimum desired center distance as required for rolling the narrowest slab for which the mill is designed, limits the radius of the gears connected to thesrespective vertical rolls. Such limited gearradius imposes relatively high pressure on the gear teeth to transmit the required load or limits the power which may be transmitted from the driving motor to the rolls.

In the mill of my invention, the vertical rolls are readily replaceable without dismantling any substantial portion of the roll stand, and the gears on the main overhead horizontal drive shaft are rigidly mounted on the shaft. A pair of generally vertical spindles are connected between the vertical rolls and a pair of vertical axis gears journaled in fixed mountings on the frame. i The spindles 2,752,804 Patented July 3, 1956 have universal connections at their opposite ends and are of sufficient length to keep the angularity in the universal joints within practical limits when the vertical rolls are moved laterally in the range of minimum and maximum settings while the gears remain in their fixed positions. The two vertical axis gears connected to the respective spindles have their axes spaced apart by a distance about equal to the average setting between minimum and maximum operating settings of the vertical rolls in the stand, and the radius of each of these gears is almost equal to half of the spacing between the axes of these gears. The result is that each vertical axis gear has a relatively large radius and this permits transmitting high power to the rolls and also permits increasing the ratio of the main drive shaft speed to the speed of the vertical rolls.

In accordance with my invention the vertical rolls are supported at their opposite ends by bearings which fit into openings onopposite ends of a pair of yokes supported by and laterally movable along intermediate and lower cross portions of the mill stand. Each yoke is adapted to be lifted as a unit out of the stand, and the vertical rolls are removable from the yokes While the latter are in the stand merely by shifting each roll laterally to the center of the stand, one at a time, and then lifting the roll axially into an open space provided between the intermediate cross portion of the stand and the gear housing at the top of the mill stand. The spindles are detached from the vertical rolls when the vertical rolls are replaced, and remain suspended from their upper universal connections in offset relation to each vertical roll as it is lifted up from the supporting yoke. The spindles are likewise readily removable and accessible for repair, using the same rig which lifts the vertical rolls in and out of the stand. The universal connec tions at the opposite ends of the spindle disconnect readily to facilitate insertion and removal of the vertical rolls and spindles, and also contain a substantial supply of lubricant between upwardly facing universal joint jaws and plates across the side of these jaws. Novel spacers between the universal bearing slippers facilitate disconnecting and repairing the universal connections.

In accordance with my invention I further provide bearings mounted around the opposite ends of each vertical roll and secured in and removed from the supporting yoke with the roll, without using bolts or the like to secure the bearings in the yoke. As a result of these improvements it is unnecessary to disassemble anything in my mill for purposes of replacing the vertical rolls, except for removing a retainer plate in the universal connection between the spindle and vertical roll, and removing any work-supporting apron which may be mounted to permit replacement of the vertical rolls and is narrow' enough to allow for rolls to come sufiiciently close together for rolling the narrowest slabs for which the mill is designed. This presents the difficulty of arranging for the apron to pass between the two conveyor rollers immediately adjacent the lower ends of the vertical rolls while removing and replacing the apron, and also to extend across and anchor on opposite sides of the aforesaid gap, which is wider than the gap between the said two conveyor rollers. In accordance with my invention this difiiculty is overcome by rounding opposite vertical edges of the apron to facilitate turning the apron about ninety degrees from its working position preliminary to lifting it between the conveyor rollers, and by providing relatively short channels indented in the adjacent cross members of the stand to receive horizontally elongated ears extending from opposite ends of the apron.

Other details, objects and advantages of the mill of my invention will become-apparent from the following detailed description and in the accompanying drawings, in which I have shown, for purposes of illustration only, a present preferred embodiment of my invention. In the drawings:

Figure 1 is an elevation facing the vertical roll side of a slabbing-blooming mill incorporating my invention;

Figure 2 is an end view, in enlarged scale, taken from the left of Figure 1;

Figure 3 is an enlarged section taken on the line III' III in Figure 2, partially broken away;

Figure 4 is an enlarged section on the line IV-IV in Figure 1, with the work support apron removed and with the portion of the mill above the lower ends of the drive spindles broken away;

Figure 5 is an enlarged detailed sectional view taken on a vertical plane through the axes of the vertical rolls and showing one of the vertical rolls with the associated lateral shifting mechanism;

Figure 6 is an enlarged view corresponding to Figure 1 but broken away to show only the connections between the lower end of one of the drive spindles and the upper end of one of the vertical rolls;

Figure 7 is a section on the line VIIVII in Figure 6;

Figure 8 is a section on the line VIII-VIII in Figure 6;

- Figure 8A is a view of the universal connection at the upper end of the drive spindle (similar to the Figure 8 view of the connection at the lower end of the spindle, but in reduced scale), with a section through the drive tongue and a plan view of the upper end of the spindle receiving the tongue;

Figure 9 is an enlarged section on the line IXIX in Figure 1, partially broken away;

Figure 10 is an enlarged section on the line XX in Figure 1, partially broken away;

Figure 11 is an enlarged section on the line XIXI in Figure 1 with the work support apron in place;

Figure 12 is an enlarged section on the line XIIXII in Figure 1 during roll replacement, showing the rolllifting mechanism in full lines in its upper position, and in chain lines in its lower position;

Figure 13 is a top view of the roll-lifting rig;

- Figure 14 is a top view of the removable work-supporting apron;

. Figure 15 is a side view of the apron shown in Figure 14; and

Figure 16 is an end view from the right of Figure 15.

Referring now more particularly to the drawings, Figures 1 and 2 show a roll stand for reduction rolling of steel slabs and'the like. The frame 10 has one section mounting a pair of horizontal working rolls 11 and 12 and another section mounting a pair of vertical working rolls 13 and 14. The horizontal rolls 11 and 12 are driven through spindles 15 and 16 and universal connections by a suitable power source (not shown), such as a pair of motors. A motor 17 drives the screwdown mechanism for the upper roll 11, which is vertically adjustable from a position against the roll 12 to a position above the working level of the vertical rolls 13 and 14. The vertical rolls 13 and 14 are driven by a single motor (not shown) through a horizontal spindle 18 and overhead drive shaft 19, and through generally vertical spindles 20 and 21 respectively connected to the upper ends of the rolls 13 and 14.

The drive shaft 19 (Figure 3) is journaled in the frame 10 and is rigidly keyed to a pair of bevel gear pinions 22 and 23, respectively meshing with a pair of bevel gears 24 and 25. The gears 24 and 25 are rigidly keyed on shafts 26 and 27 journaled in the frame 10. The shafts 26 and 27 drive the spindles 20 and 21 through universal joint connections 28 and 29. The connections 28 and 29 are identical and the connection 28, for example, com- 4 prises jaws 30 fixed to the spindle 20, a tongue 31 extending from a coupling fixed to the shaft 26, a pair of slippers 32 between the jaws 30 and tongue 31, cover plates 31a removably mounted across the jaws 30 to retain lubricant around the tongue 31 and slippers 32 in the span between the jaws 30, and a pin 33 which extends through aligned openings in the tongue 31 and slippers 32. The tongue 31, pin 33 and slippers 32 are connected to the gear shaft 26, and the spindle 20 is suspended therefrom by the grip of its jaws 30 around the slippers 32. The spindle 20 is detached from the tongue 31 by opening normally plugged openings 33a in the jaws 30 and tapping out the pin 33, and one of the cover plates 31a is preferably removed also to allow the jaws 30 and unpinned slippers 32 to be removed horizontally from the'tongue 31. The opening between the jaws is semicylindrical and grooved to allow the semi-cylindrical and flanged outer surfaces of the slippers 32 to move in the jaws 30 around but not along the axis of curvature of the jaws, while the inner flat surfaces of the slippers slide freely against the flat tongue 31 about the axis of the pin 33 (the spacer 32a is slidable along and within said jaw groove).

The lower ends of the vertical spindles 20 and 21 are connected to the upper ends of the vertical rolls 13 and 14 through universal joint connections 34 and 35 (Figure l). The connections 34 and 25 are identical and the connection 34, for example (Figures 6-8), comprises a tongue 37 extending integrally from the spindle 20, a pair of jaws 38 extending integrally from a coupling 39, and a pair of slippers 40 between the tongue 37 and jaws 38. The roll 13 has an outer neck 41 fastened within the coupling 39. The connection 34 is similar in structure to the connection 28 at the upper end of the spindle 20 except that the slippers 40 are not connected by a pin like the pin 33. The omission of such pin makes it mechanically unnecessary to provide openings through the slippers 40, but these are preferably included for the sake of making parts interchangeable to simplify assembly and reduce inventories of spare parts. The tongue 37 is free to slide axially between the slippers 40 in order to permit the spindle 20 to swing from the fixed pivot point of its upper connection 28, and is restrained from sliding sidewise from between the slippers 40 by a pair of keeper plates 42 across the opposite sides of the jaws 38 in slidable engagement with the sides of the tongue 37. The keeper plates 42 are dovetailed and wedged in slots on opposite sides of the jaws 38, are locked in place by bolts 42a, and not only retain the side edges of tongue 37 but also retain a good supply of lubricant around the tongue 37 and slippers 40 between the jaws 38. The tongue 37 has its opposite sideedges curved in semicircles about an axially-located central point in the tongue so that the curved sides will continue to engage both keeper plates 42 in all straight and inclined positions of the spindle 20. As the axis of rotation of the spindle 20 is inclined from the vertical as viewed in Figure 6 its axis will continue to intersect the axis of the roll 13 at approximately the same point (see the center of the circular opening for the omitted connecting pin in Figure 6). When the spindle 20 is rotated ninety degrees the curvature of the slippers 40 cause the roll axis to pass through said fixed point at all working angles of inclination of the spindle 20 (see Figure 7). As a result, the spindle 20 is effective to drive the roll 13 throughout the necessary range of angular adjustment and axial displacement of the spindle 20 relative to the roll 13.

A curved spacer member 43 is inserted in the semicylindrical opening between the jaws 38 before the slippers 40 are inserted. The spacer 43 is slidable in the opening between the jaws 38 about the same axis as the slippers 40 and positions the slippers 40 to receive the tongue 37 when the spindle 20 is connected to the roll 13. The spacer 43 also prevents the slippers 40 from sliding down to concentrate their weight on the outer end Of the tongue 37.

The neck 41 at the extreme upper end of the 1ro1l13 is of reduced diameter and has a splined connection with the coupling 39. A radially extending bolt 43a extends through the coupling 39 into the neck 41 for lifting the roll 13 by the coupling 39 (Figures 6 and 7). An intermediate neck 44at the upper end of the roll 13 is journaled in a supporting yoke end 45. The bearing assembly comprises a cylindrical outer case 46 slidably received in a cylindrical opening in the yoke end 45 and having an outer flange 47 overlapping the yoke end 45. An outer bearing race48 extends around the inner surface of the case 46, an inner bearing race 49 extends around the outer surface of the neck 44, and between these races a set of conical roller bearings 50 are mounted to take radial and axial load. An upper retaining ring 51 is bolted to the case 46 to confine the upper end of the outer race 48, and a second upper retaining ring 52 is keyed on an upper extension of the neck 44 between the upper end of the inner race 49 and a lock ring 53. A further upper extension of the neck 44 is grooved to receive a split ring 52a, and the lock ring 53 is first screwed around ring 52a and then is secured by a bolt 53a to the ring 52. The lower end of the case 46 is flanged inwardly to retain the lower end of the outer race 48. The lower end of the inner race 49 is confined by a ring 54 extending between the lower end of the race 49 and the upper end of the main body of roll 13. Seals between the ring 54 and the lower end of the case 46 retain lubricant for the bearing rollers 50.

The coupling 39 has a shoulder 55 to receive a lifting rig for moving the roll 13 vertically through the opening in the yoke end 45, and the roll 13 has a shoulder 56 between its main body and neck 44 to engage the ring 54 for lifting the bearing assembly with the roll 13 when the coupling 39 is lifted. The roll 13 and the bearing assembly within the case 46 can only be lifted with the coupling 39, however, when the yoke end 45 and roll 13 are in the center ofthe roll stand.

The yoke end 45 has oppositely extending flanges which ride in parallel channels along a pair of spaced intermediate cross members 57 and 58 integral with the frame 10 (Figures 4 and 9). The flange 47 of the bearing case 46 has oppositely extending cars 59 which slide under overlapping retaining pieces 60 and 61 respectively bolted to the cross members 57 and 58. The retaining pieces 60 and 61 overlap and hold the cars 59 against upward movement when the roll 13 is laterally displaced from the center of the roll stand, but release the cars 59 when the roll 13 is in the center of the roll stand so that the bearing case 46 and roll 13 can be lifted up through the yoke end 45 by means of a lifting fork inserted under the shoulder 55 of the coupling 39. The cars 59 have flat ends riding against the respective cross members 57 and 58 to prevent rotation of the case 46 as the roll 13 is rotated by the spindle 20. i

The roll 13 is symmetrical at its opposite ends, so that it may be used in one position and then reversed and used again before refinishing. The lower neck 62 of the roll 13 corresponding to the upper neck 44 mounts identical inner and outer bearing races with bearing rollers therebetween but the surrounding bearing case 63 (Figure difiers from the corresponding bearing case 46 around the upper neck 44. The case 63 is of smaller diameter than the upper case 46 in order to facilitate passing the case 63 and its small outer joint-shielding flange 64 through the opening in the yoke end 45 during replacement of the roll 13. A ring 65 forms a lower extension of the case 63 and has four spaced dependent tapering fingers 65a between which upwardly extending bolts (not shown) connect the ring 65 to the case 63. The upper end of case 63 overlaps and rests on the top of the outer bearing race, which is supported by the inner race through the intermediate thrust bearing rollers. The inner race rests on a ring 66 held in place by a ring 67 screwed around a split ring (notshown) inserted in a groove around neck 62, the rings 66 and 67 being identical in form and mounting with the rings 52 and 53 at the upper end of the roll 13. An upwardly extending inner flange of the ring 65 abuts the lower end of the outer bearing race, and seals between the rings 65and 66prevent escape of lubricant from the adjacent bearings.

The lower bearing case 63 and its lower extension ring 65 are slidably received in a vertical opening in a yoke end 68. which is horizontally slidable between parallel vertical bearing plates 69 secured to a pair of spaced lower cross members 70 and 71 of the frame 10 (Figures 5 and 10). The weight of the yoke end 68 is supported by an integral yoke connection 72 extending vertically between the yoke ends 45 and 68, and the resultant complete yoke 72a consisting of ends 45 and 68 and connection 72 may readily be lifted vertically between the intermediate across members 57 and 58 when the yoke is inserted in and removed from the frame 10. The four dependent tapered fingers 65a of ring 65 are slidably received in corresponding notches in a lower extension 680: of the yoke end 68 for the purpose of preventing the case 63 from rotating while the spindle 20 is driving the roll 13.

A conventional pair of horizontal screws 73 and 74 engage pads secured in the upper and lower yoke ends 45 and 68 to move the yoke 72a and roll 13 horizontally in the direction of the roll 14, and a piston 82 is connected by parallel spaced links 76 and pin 77 to the center of the yoke connecting member 72 to draw the yoke 72a and roll 13 horizontally away from the roll 14. The screws '73 and 74 are rotated by gears 78 and 79 meshing with a common gear 30 driven by a motor 81 and connected to the respective screws 73 and 74 by keys 73a and 7411. These keys slide in longitudinal slots in the screws 73 and 74 as the latter move lengthwise while turning in fixed nuts 73b and 74b. The piston 82 is horizontally slidable in a cylinder 75 secured in the frame 10 and conventional means supply hydraulic fluid to the cylinder 75 to force the piston 82 and roll 13 away from the roll 14 while the screws 73 and 74 are simultaneously moved in the same direction to permit this movement. Conventional means are also provided to exhaust hydraulic fluid from the cylinder 75 while the screws 73 and 74 are pushing theyoke 72a and roll 13 toward the roll 14.

The roll 14 is similarly mounted and is independently movable toward and from the roll 13 by like means mounted on the other side of the roll stand (Figure 1) so that the rolls, 13 and 14 may be spaced equally from the center of the roll stand for rolling purposes and may be moved alternately to the center of the roll stand for replacement purposes. In Figures l, 4, 5 and 9-11 the parts shown with primed designating numerals have the same relation to the roll 14 as the parts with the corresponding unprimed numbers described above in connection with roll 13.

The means for conveying workpieces between the vertical rolls 13 and 14 and the horizontal rolls 11 and 12 include a series of horizontal conveyor rollers with their upper surfaces at a level somewhat below the upper surface of the lower horizontal roll 12 (Figures 4 and 11). These conveyor rollers are reversibly driven by motors 82a and include a pair of conveyor rollers 83 and 84 extending adjacent and along opposite sides of the lower ends of the vertical rolls 13 and 14. The gap between the conveyor rollers 83 and 84 must be: at least suflicient to permit the lower. bearing case 63 of the roll 13, and the corresponding case of the roll 14, to be moved vertically therebetween. In order to prevent workpieces from tilting down into this gap an apron 85 is mounted transversely between the lower cross members 70 and 71 at the center ofthe frame 10. The apron 85 is relatively narrow in order to permit the rolls 13 and 14 to come sufficiently close together for rolling. minimum sections, and it is readily removable when the space it occupies mustbe-cleared to receive the lower ends of the rolls 13 and 14 during roll replacement operations. The top ofthe apron 85 has a horizontal surface 86 for slidably supporting workpieces tilting below the top level of the conveyor rolls 83 and 84 (one or more rollers may be substituted for the surface 86 if desired). A pair of ears 87 and 88 extend from opposite sides of the apron 85 to rest on the horizontal surfaces of opposite channels 70a and 71a indented in the respective lower cross members 70 and 71. The cars 87 and 88 are horizontally elongated on both sides of the apron 85 to prevent sidewise tilting of the table, and to stay on the horizontal surfaces of the channels 70a and 71a even if the apron 85 is twisted to some extent out of its original position during operation of the mill. The channels 70a and 7111 are not much longer than the ears 87 and 88, in order to confine the ends of the ears 87 and 88 against excessive shifting during operation of the mill and to oppose twisting of the apron 85 about its central vertical axis except when the apron is centered between the ends of the channels 70a and 71a. The lower portion of the apron 85 below the ears 87 and 88 has vertical edges 89 and 90 abutting adjacent sides of the cross members 70 and 71, and these edges 89 and 90 engage the cross members 70 and 71 in a snug fit to hold the apron 85 in place as workpieces pass along its upper surface 86. The apron 85 has an opening 91 to receive a hook for carrying the apron to and from its working position. When the apron is being inserted in place it is lowered between the conveyor rollers 83 and 84 while extending generally parallel to these rollers, and then the apron is rotated ninety degrees about its central vertical axis to swing the ears 87 and 88 under the conveyor rollers 83 and 84 onto the cross members 70 and 71. In order to permit this swinging movement and at the same time to provide a snug fit of the apron 85 with the cross members 70 and 71 along their abutting vertical edges the outer vertical surfaces of the cars 87 and 88 and of the abutting edges 89 and 90 are curved cylindrically about the central vertical axis through the center of the opening 91.

The vertical rolls 13 and 14 are successively inserted and replaced by means of a lifting rig 92 suspended from a principal weight-supporting crane hook 93 and a secondary crane hook 94 (Figures 12-15). The front end of the rig 92 has a pair of lifting arms 95 with a curved web 96 therebetween to center the coupling 39 between the arms 95 with its shoulder 55 overlying and resting on the arms 95. The arms 95 similarly engage the corresponding coupling for lifting the roll 14. When the arms 95 are in place against the coupling 39 notches 97 in the top of the respective arms 95 receive the lower projecting ends of keeper plates 42 to prevent the coupling 39 from slipping axially from between the arms 95. An eye member 98 is secured to an intermediate portion of the rig 92 for receiving the principal crane hook 93, and a second eye member 99 is secured adjacent the rear end of the rig 92 to receive the balancing crane hook 94. A counterweight 100 is secured to the rear end of the rig 92 to overbalance the weight of the vertical roll 13 and its associated elements suspended from the coupling 39, so that the secondary crane hook 94 all be effective to control the angular position of the rig 92 about the principal crane hook 93. v

When the roll 13 is to be removed the apron 85 is removed by rotating it ninety degrees and then lifting it out from between the adjacent conveyor rolls 83 and 84. The spindle 20 is turned until the tongue 37 is parallel to the cross members of the frame, the keeper plate 42 facing to the left as shown in Figure l is removed, and the screws 73 and 74 are operated to push the yoke ends 45 and 68 and roll 13 to the center of the roll stand, as indicatedin chain lines in Figure 5, thus freeing the ears 59 from the overlying retaining pieces 60 and 61 and permitting the tongue 37 to slide out from between the jaws 38 as the roll 13 is shifted into laterally 8 offset relation to the spindle 20. The rig 92 is then brought into lifting engagement with the coupling 39 (dotted line position in Figure 12), guided by a pair of channel members 102 and 103 (Figure 9), and is lifted vertically until thelower end of the roll 13 is above the upper surface of the intermediate cross member 58 (full line position in Figure 12). Head room for the upper end of the coupling 39 is provided by a recess 101 (Figures 1, 3 and 12) in the bottom of the case around the drive gears 24 and 25. This recess is preferably provided with sidewalls slanting outwardly to guide the upper end of the roll into position preliminary to lowering it into its Working position in the frame. The rig 92 is then withdrawn horizontally (to the right as shown in Figure 12) until the roll 13 is entirely clear of the frame 10.

When the roll 13 is to be returned into place it is brought 1 back horizontally (to the left as shown in Figure 12) until it is again centered in position over the openings in the centered yoke ends 45 and 68. After roll 13 is lowered into these openings and the lifting rig 92 is withdrawn the roll 13 is shifted laterally to bring the jaws 38 around the tongue 37. The keeper plate 42 which had been removed is replaced and the roll is ready for operation. When rolls 13 and 14 are both ready the apron is lowered and turned into place and rolling operations can resume. The return of the roll 13 to its vertical position in the roll stand is facilitated by the vertical sides of the recess 101 opening toward the advancing coupling 39 to channel it into the recess 101.

The upper ends of spindles 20 and 21 have shoulders 104 and 105 of the same size and shape as the shoulder 55 of coupling 39 so that the rig 92 can engage the shoulders 104 and 105 to lift the spindles 20 and 21 in addition to being able to lift the rolls 13 and 14. This is useful not only for purposes of inserting and removing the spindles 20 and 21 but also for the purpose of supporting the spindles while their bearing slippers (such as the slippers 32) are replaced periodically. When the spindle 20, for example, is to be removed, the spindle 20 is turned until the tongue 37 is parallel to the cross members of the frame, the keeper plate 42 facing to the left as shown in Figure l is removed, and the vertical roll 13 is shifted to the center of the stand 10, thereby freeing the spindle 20 from the roll 13. The rig 92 is then inserted under the shoulder 104 and the pin 33 is removed after unplugging the openings 33a. One of the cover plates 31a (Figure 8A) at the side of the tongue 31 is removed and the rig is then moved horizontally to carry the spindle 20 away from the roll stand. For purposes of replacing the spindle 20 this procedure is repeated in reverse, except that the tongue 37 of the spindle 20 is reinserted between the jaws 38 by shifting the roll 13 into axial alignment with the spindle 20 after the latter has again been pinned to tongue 31. l

While I have illustrated and described a present preferred embodiment of the invention it will be recognized that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

1. A mill for reduction rolling of metal pieces such as slabs, comprising a pair of spindles with universal connections at their opposite ends, a pair of vertical axis bevel gears connected to drive the upper ends of the spindles, a pair of horizontal axis bevel gears fixed to a drive shaft and driving the vertical axis gears, a pair of vertical working rolls detachably connected to the lower ends of the spindles, a pair of opposed laterally shiftable yokes, one for each working roll, each having upper and lower ends with aligned vertical openings therethrough, roller bearing assemblies carried at opposite ends of the rolls, each roll being supported in one of the yokes with the bearing assemblies at the ends of the roll received in the openings at the ends of the yoke, the rolls and the bearing assemblies being of smaller diameter than said upper openings so that each roll can beliftable with its bearing assemblies out of its yoke through said openings, a frame having a pair of cross members between which the upper ends of the yokes are laterally slidable toward and away from each other, and a pair of opposed retaining means one for each roll bearing assembly secured to and extending along the opposite ends of one of the cross members and slidably overlapping portions of the respective upper bearing assemblies, thereby holding down the rolls while permitting lateral movement thereof with their yokes, said pair of retaining means being spaced from each other at the center of the frame to provide a clearance to permit each roll to be lifted out of its yoke while centered in the frame.

2. Apparatus according to claim 1 wherein each of the upper bearing assemblies includes an outer case received in the adjacent yoke opening and having an extension slidable along at least one of the upper cross members to prevent the case from rotating with the adjacent roll.

3. Apparatus according to claim 1 wherein each of the lower bearing assemblies has an outer case with dependent fingers interlocked with a portion of the lower yoke end to prevent rotation of the case with the adjacent roll.

4. A mill for reduction rolling of metal pieces such as slabs, comprising a pair of spindles with universal connections at their opposite ends, a pair of vertical axis bevel gears connected to drive the upper ends of the spindles, a pair of horizontal axis bevel gears fixed to a drive shaft and driving the vertical axis gears, a pair of vertical working rolls detachably connected to the lower ends of the spindles, a pair of yokes in which the rolls are respectively journaled and from which the rolls are vertically liftable, the yokes being laterally shiftable in the frame to adjust the setting of the vertical rolls during rolling operations, a pair of retaining means secured to the frame and holding down the rolls while permitting lateral movement thereof with their yokes, said pair of retaining means being spaced on opposite sides of the center of the frame to permit each roll to be lifted out of its yoke while centered in the frame, a pair of workpiece conveyor rollers extending transversely across the lower ends of the vertical rolls adjacent opposite sides thereof, a pair of spaced frame cross members eXtencling beneath the respective conveyor rollers and guiding the lower ends of the yokes therebetween, and a workpiece supporting apron removably mounted across said cross members between the vertical rolls and across the gap between the adjacent conveyor rollers.

5. Apparatus according to claim 4 in which said apron has an opening therethrough to receive a crane hook, and has opposite edges abutting said cross members and curved about a vertical axis through the center of said opening, whereby the apron is firmly emplaced and is rotatable about said axis preliminary to withdrawing it between the adjacent conveyor rollers.

6. Apparatus according to claim 4 in which the apron is relatively narrow between the vertical rolls and has a pair of ears projecting from its opposite ends to overlap and rest in the respective cross members, said ears extending horizontally on both sides of the apron in the direction of the vertical rolls to oppose tilting in the direction of the vertical rolls.

7. Apparatus according to claim 4 in which the respective cross members have oppositely facing channels indented therein and extending horizontally across the center of the frame, and in which the apron has extensions from its ends overlapping the horizontal surfaces of said channels along the greater part of the length of the channels and abutting the vertical sides of said channels, the vertical abutting edges of said extensions being curved about a central vertical axis through the apron.

8. A removable apron for supporting metal slabs and the like passing between vertical work rolls, comprising a body of narrow width and substantial length and depth,

with an upper lengthwise surface for slidably supporting metal slabs and the like, with a central opening for receiving a crane hook, and with ears extending from its opposite ends to overlie and rest on supporting frame memhere, said ears projecting substantially beyond the general width of the body on each side thereof to oppose tilting of the apron. i

9. Apparatus according to claim 8 in which the ears have outer edges curved about the central vertical axis of the apron to facilitate rotating the apron preliminary to seating and unseating it in a mill stand.

10. A mill for reduction rolling of large metal pieces, comprising a pair of vertical working rolls, a fixed frame in which the rolls are jornaled and laterally movable, a horizontal drive shaft spaced above the rolls, a pair of gears rigidly secured to said shaft, 21 pair of second gears meshing with the respective first gears and journaled in the frame below the first gears to rotate about fixed vertical axes, a casing forming part of the frame around said second gears with a recess in the casing adjacent the center of the frame for receiving the upper end of one of the vertical work rolls during roll replacement operations, the vertical sides of said casing defining said recess being arranged to slant outwardly to guide the upper end of one of the vertical rolls into said recess preliminary to lowering the roll into its working position in the frame, a pair of generally vertical spindles having universal connections at their opposite end respectively connected to said second gears and to the upper ends of the rolls when in working position, said frame having a cross portion spaced sufficiently below said recess to clear the lower end of a roll while it has its upper end in said recess and laterally-movable means in said cross portion with an opening therethrough in which the upper end of one of the vertical rolls is journaled while in working position and through which the said roll is vertically movable to lower it into working position and to lift it therefrom.

11. Apparatus according to claim 10 in which guide means are mounted on the top of said cross portion of the frame to guide the lower end of one of the vertical rolls into position over said opening while the upper end of the roll is guided by said casing into said recess during horizontal movement of the roll into the frame preliminary to lowering it through said opening.

12. A mill for reduction rolling of metal pieces such as slabs, comprising a pair of spindles with universal connections at their opposite ends, a pair of vertical axis bevel gears connected to drive the upper ends of the spindles, a pair of horizontal axis bevel gears fixed to a drive shaft and driving the vertical axis gears, a pair of vertical working rolls detachably connected to the lower end of the spindles, a pair of opposed laterally shiftable yokes, one for each working roll, each having upper and lower ends with aligned vertical openings therethrough, roller bearing assemblies around the opposite ends of the vertical rolls and received in openings in the yoke ends, the rolls and bearing assemblies being of smaller diameter than said upper openings so that each roll and the bearing assemblies around its ends are axially liftable through said yoke openings, and a pair of opposed retaining means, one for each roll bearing assembly secured to and extending along the opposite,

sides of one of the upper cross members and slidably overlapping portions of the bearing assemblies at the upper ends of the respective vertical rolls, thereby holding down the rolls and their supporting yokes, said pair of retaining means beingspaced from each other at the center of the frame to provide a clearance to permit each roll to be lifted out of its yoke while centered in the frame.

13. A mill for reduction rolling of metal pieces such as slabs, comprising a pair of spindles with universal connections at their opposite ends, a pair of vertical axis bevel gears connected to drive the upper ends of the spindles, a pair of horizontal axis bevel gears fixed to a drive shaft and driving the vertical axis gears, 21 pair of vertical working rolls detachably connected to the lower ends of the spindles, a pair of opposed laterally shiftable yokes, one for each working roll, each having upper and lower ends with aligned vertical openings therethrough, bearing assemblies carried at opposite ends of the rolls, each roll being supported in one of the yokes with the bearing assemblies at the ends of the roll received in the openings at the ends of the yoke, the rolls and the bearing assemblies being of smaller diameter than said upper openings so that each roll can be liftable with its bearing assemblies out of its yoke through said openings, a frame having a pair of cross members between which the upper ends of the yokes are laterally slidable toward and away from each other, and a pair of opposed retaining means, one for each roll bearing as sembly secured to and extending along the opposite ends of one of the cross members and slidably overlapping portions of the respective upper bearing assemblies, thereby holding down the rolls while permitting lateral 12 movement thereof with their yokes, said pair of retaining means being spaced from each other at the center of the frame to provide a clearance to permit each roll to be lifted out of its yoke While centered in the frame.

References Cited in the file of this patent UNITED STATES PATENTS 749,823 Keller Jan. 19, 1904 1,359,601 Iverson Nov. 23, 1920 1,364,989 Geer Jan. 11, 1921 1,578,994 Holmes Mar. 30, 1926 1,880,468 Nye Oct. 4, 1932 2,011,686 Mikaelson Aug. 20, 1935 2,049,842 Kling Aug. 4, 1936 2,305,594 Backus Dec. 22, 1942 2,305,703 Smith Dec. 22, 1942 2,311,075 OMalley Feb. 16, 1943 2,332,859 Kreissig Oct. 26, 1943 2,565,928 OMalley Aug. 28, 1951 2,618,941 Iverson Nov. 25, 1952 

1. A MILL FOR REDUCTION ROLLING OF METAL PIECES SUCH AS SLABS, COMPRISING A PAIR OF SPINDLES WITH UNIVERSAL CONNECTIONS AT THEIR OPPOSITE ENDS, A PAIR OF VERTICAL AXIS BEVEL GEARS CONNECTED TO DRIVE THE UPPER ENDS OF THE SPINDLES, A PAIR HORIZONTAL AXIS BEVEL GEARS FIXED TO A DRIVE SHAFT AND DRIVING THE VERTICAL AXIS GEARS, A PAIR OF VERTICAL WORKING ROLLS DETACHABLY CONNECTED TO THE LOWER ENDS OF THE SPINDLES, A PAIR OF OPPOSED LATERALLY SHIFTABLE VOKES, ONE FOR EACH WORKING ROLL, EACH HAVING UPPER AND LOWER ENDS WITH ALIGNED VERTICAL OPENINGS THERETHROUGH ROLLER BEARING ASSEMBLIES CARRIED AT OPPOSITE ENDS OF THE ROLLS, EACH ROLL BEING SUPPORTED IN ONE OF THE YOKES WITH THE BEARING ASSEMBLIES AT THE ENDS OF THE ROLL RECEIVED IN THE OPENINGS AT THE ENDS OF THE YOKE, THE ROLLS AND THE BEARING ASSEMBLIES BEING OF SMALLER DIAMETER THAN SAID UPPER OPENINGS SO THAT EACH ROLL CAN BE LIFTABLE WITH ITS BEARING ASSEMBLIES OUT OF ITS YOKE THROUGH SAID OPENINGS, A FRAME HAVING A PAIR OF CROSS MEMBERS BETWEEN WHICH THE UPPER ENDS OF THE YOKES ARE LATERALLY SLIDABLE TOWARD AND AWAY FROM EACH OTHER, AND A PAIR OPPOSED RETAINING MEANS ONE FOR EACH ROLL BEARING ASSEMBLY SECURED TO AND EXTENDING ALONG THE OPPOSITE ENDS OF ONE OF THE EROSS MEMBERS AND SLIDABLY OVERLAPPING PORTIONS OF THE RESPECTIVE UPPER BEARING ASSEMBLIES, THEREBY HOLDING DOWN THE ROLLS WHILE PERMITTING LATERAL MOVEMENT THEREOF WITH THEIR YOKES, SAID PAIR OF RETAINING MEANS BEING SPACED FROM EACH OTHER AT THE CENTER OF THE FRAME TO PROVIDE A CLEARANCE TO PERMIT EACH ROLL TO BE LIFTED OUT OF ITS YOKE WHILE CENTERED IN THE FRAME. 